Thomas steahan shenston



(No Model.)

T. S. SHENSTON.. GAR BRAKE.

No. 426,336. Patented Apr. 2z, 1890..-

UNITED STATES PATENT OFFICE..

THOMAS STRAIIAN SHENSTON, OF BRANTFORD, ONTARIO, CANADA.

CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 426,336, dated April 22l 1890.

Application tiled February 20, 1890. Serial No. 341,192. (No model.)

To all whom it may concern:

Be it known that I, THOMAS STRAHAN SHEN- STON, a subject of the Queen of Great Britain, and a resident of Brantford, in the Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Oar-Brakes, of which the following is a specification.

This invention has reference to improvements in car-brakes in which a brake-shoe is forced into contact with the tread of a wheel by means of screws acting directly on such brake-shoes and operated from some convenient point in the car by means of suitable iiexible connections, and in which the application and maintenance of great force upon the brake-shoes are insured without subjecting the intermediate connections to continued strain in order to effect such result.

The improvement therefore consists, essentially, in mounting a shaft having its ends threaded in opposite directions, so as to extend longitudinally between the treads of each pair of wheels on each side of the car-truck, brake shoes mounted upon such threaded ends of each shaft, and chain-gear extending from such shafts to some suitable point on the car from which the chain may be operated to rotate the shafts simultaneously, and thus carry the brake-shoes into or out of contact with the treads of the truck-wheels, all as will hereinafter more fully appear.

In the accompanying drawings I have represented a preferred construction embodying my improvements; and it will be understood that I am by no means limited by such identical structures, as they may be variously modified without departing from the principles of the invention.

In the drawings, Figure 1 is a side elevation of the chain gearing and connections, together with the two shafts operated thereby. Fig. 2 is a plan view of the same with the brakewheel and guide-pulley shafts in section; and Fig. 3 is an elevation, partly in section, of the truck with the brake-shoes and operatingshaft applied.

Referring now to the drawings, there are shown two shafts l 2, each of which is reduced in diameter at its ends and there provided with right and left handed screwthreads, respectively, as shown at 3. Cen

trally upon each shaft there is mounted a sprocket-wheel 4, andthese shafts are mounted in hangers 5, depending from opposite sides of a truck-frame 6. The hangers are so located that each shaft will extend longitudinally between each pair of truck-wheels 7 of the truck, with the screw-threaded ends 3 projecting beyond the hangers and the sprocketwheel 4 confined between the same.

Upon the screw-threaded ends 3 of the shafts 1 and 2 are mounted brake-shoes 8, each shoe being provided with a boss 9, in which is formed a nut for the respective screw-threaded end of the shaft, andthe bearing-faces of these brake-shoes are placed as close as practicable to the treads of the wheels, so that but a limited rotation of the shaft is necessary in order to force the brake-shoe into firm contact with the tread of the wheel.

It will be understood that the brake-shoes are held against rotation either by engaging the flanges of the wheels or bysuitable guides, and that the right and left hand screw-threads on the shaft will tend to move the brakeshoes simultaneously in opposite directions, the shaft itself being held against longitudinal movement by the brackets 5 engaging the sides of the sprocket-wheel 4. It will likewise be observed that the screw-threaded shaft admits of the application of great power to the brake-shoes to force them strongly against the treads of the wheels, and that when the brakes are so applied they will remain in such position until the shaft is positivelyrotated in the opposite direction, thus obviating the use of detents and all strain on the connections employed for rotating the shaft.

The brakes are operated from a suitable shaft 10, extending through the car-platform 11, and carrying on its upper end a brakewheel l2, and below the platform 11 a sprocket-Wheel13. Around each sprocket-wheel 4 there extends a section let of sprocket-chain, these chains being connected togetheron one side by a length 15 of ordinary link-chain and on the other side by similar chains 16 17, extending to the respective ends of a sprocketchain section 1S, passing around the sprocketwheel 13 on the brake-wheel shaft 10, the said chains 16 and 17 also passing around a guide-pulley 19, mounted upon a shaft 20, having suitable bearings below the car-plat- IOO form 11 at some convenient point between the shafts 1 and 2, so that the direction of the chains 16 and 17 may be changed, since, as Will be observed, the sprocket-Wheel 13 on the shaft is necessarily located at some distance'frorn the car-truck, in order to be conveniently placed on the car-platform, and the sprocket-Wheel 13 rotates in a horizontal plane, while the sprocket-wheels 4 rotate in a vertical plane. If now the brake-wheel 12 be manipulated to rotate the shaft 10 and sprocket-wheel 13 in the direction of the arrow,

Fig. 2, the chain 16 will be drawn toward the said sprocket-Wheel 13, while the chain 17 ,will be free to move away from it. This movement of the chain 16 will cause it to carry the sprocket-chain 14 connected to it in a direction to rotate the shaft 2 in such manner that the brake-shoes carried thereby will be forced toward and into contact With the Wheel-treads; and since the other sprocket-chain 14 is connected to the rstmentioned sprocket-chain 14 by the chain it will participate in the movement described and rotate the sprocket-wheel 4 of the shaft 1. At the same time this Inovement will take up the slack of the chain 17. The threaded ends of th'e shaft 1 are so arranged that When moved in the manner described they will force the brake-shoes against the treads of the respective wheels simultaneously with the like movements caused bythe rotation of the shaft 2. Thus it will be seen that when the brake-wheel is' manipulated in screws to draw the brake-shoes away from the Wheels. 7

Since the sprocket-chain is of much more costly construction than an ordinary linkchain, and since the chain-connections have but a limited movement, only so much sprocket-chain is used as is necessitated by the size and number of the sprocket-wheels.

I-Iaving now fully described my invention, I claim and desire to secure by Letters Patent- 1. In a car-brake, the combination of a pair *of brake-shoes oneach side of the truck, and right and left handed screw-shafts, one for each pair of brake-shoes, for simultaneously operating the same, with a brake Wheel mounted on the platform of the car, and chain-gearing connecting the brake-wheel with the screw-shafts, substantially as described.

2. In a car-brake, the combination of a pair of brake-shoes on each side of the truck, right and left handed screw-shafts, one for each pair of brake-shoes, for simultaneously operating the same, and a sprocket-wheel on each shaft, With a brake-wheel mounted on the platform of the car, a sprocket-wheel operated by the brake-wheel, and chain-connections therefrom to the sprocket-wheels on the screw-shafts, substantially as described.

3. In a car-brake, the combination of a pair of brake-shoes on each side of the truck, and a right and left handed screw shaft and sprocket-Wheel thereon for each pair of brakeshoes, with a brake-Wheel and sprocket-Wheel operated thereby, and chain-gearing connecting the brake-wheel and screw-shafts for operating the latter simultaneously, and embracing sections of sprocket-chain at the said sprocket-Wheels, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

THOMAS STRAIIAN SHENSTGN. lVitnesses:

MINNIE A. WINTER, JOHN FoULDs. 

